All versions of the trinket have a click effect to gain 1750 max health (kind of like the old lifegiving gem effect), along with a passive effect (your choice of 47 spell damage, 40 spell crit rating, 80 attack power, 40 melee crit rating, or 88 healing). (source)

They cost badges of justice, which will also be available off Kara and Zul Aman bosses. (source)

They're open to all classes. The click effects share a cooldown though, so you won't be able to stack that effect. (source)

One player was very unhappy that he would be forced to PvE just so he can got back to PvP'ing. Kaplan responded that experiencing different parts of the game isn't such a bad thing and stood his ground on that decision. I wonder if he'd feel the same if he forced PvE players into PvP for better gear.